Reimported FBX doesn't react to light properly
I downloaded a space station model from the asset store that I want to use in my game as a final level, for my game I wanted to remove one of the panels on the outside of the model to make one of the entrances wider.
I have never done any 3D modelling before but managed to download blender, import the model as an FBX and export and re-import it back to Unity. I copied the material properties of the original model over to my new one so that I could reapply the textures, below is my result:
The only issue is that when inside the station my new one (on the left) seems to be a lot darker and the texture still seems different, here is the new camera view (left) and old camera view (right):
What could be causing this? I have never messed around with FBX files before so forgive me if it's something obvious, any help would be appreciated. Thanks.